docs: def no_missing_parents(data_wrapper):
      '''Check that all points have existing parents
      Point's parent ID must exist and parent must be declared
      before child.
  
      Returns:
          CheckResult with result and list of IDs that have no parent
      '''
      db = data_wrapper.data_block
      ids = np.setdiff1d(db[:, COLS.P], db[:, COLS.ID])[1:]
      return CheckResult(len(ids) == 0, ids.astype(np.int) + 1)